Gait asymmetry is characterized as the dynamic differences between contralateral limbs and is generally caused by disease, age, clinical interventions, or limb dominance. A number of mobile gait assessment systems have been developed for evaluation of gait asymmetry in persons with leg length discrepancy (LLD) or simulated leg length discrepancy (sLLD).
In the last few decades, gait analysis has been constrained to studies involving motion capture and the obligatory body markers and force mats. These constraints limit normal locomotion and remove important variation representative of each individual's gait. In addition to the behavioral constraints added by the non-mobile common gold standard measurement tools, high prices also deter medical professionals from making motion studies common practice.
More recent studies regarding gait analysis focus on using inertial measurement units (IMU) to assess asymmetry in gait, extracting gait features, or differentiating disease states. However, these designs have limited applications for LLD or sLLD, because LLD or sLLD leads to significant changes to gait in ground reaction forces (GRF). As a result, the representative kinetic components of GRF cannot be effectively measured by IMU sensors.